Engine Noise Identification and Location

For information on Ford Color Coded Illustrations refer to OEM COLOR CODING INFORMATION

1. NVH symptoms should be identified using the diagnostic tools and techniques that are available. For a list of these techniques, tools, an explanation of their uses and a glossary of common terms, For additional information, refer to: Noise, Vibration and Harshness (NVH) . Since it is possible that any one of multiple systems may be the cause of the symptom, it may be necessary to use a process of elimination type of diagnostic approach to pinpoint the responsible system.
2. Verify the customer concern by operating the engine to duplicate the condition.
3. Check the engine oil level and check the oil for contamination. Low engine oil level or contaminated oil are a common cause of engine noise. If the oil is contaminated, the source of the contamination must be identified and repaired as necessary.
4. Visually inspect for obvious signs of mechanical damage.
5. If the inspection reveals obvious concerns that can be readily identified, repair as necessary.
6. NOTE: Make sure to use the latest scan tool software release.

   If the cause is not visually evident, connect the scan tool to the DLC.

7. NOTE: The VCM LED prove out confirms power and ground from the DLC are provided to the VCM.

   If the scan tool does not communicate with the VCM:

   • check the VCM connection to the vehicle.
   • check the scan tool connection to the VCM.
   • check for No Power To The Scan Tool, to diagnose no power to the scan tool.For additional information, refer to: Controller Area Network (CAN) Module Communications Network .

8. If the scan tool does not communicate with the vehicle:
   • verify the ignition key is in the ON position.
   • verify the scan tool operation with a known good vehicle.
   • to diagnose no response from the PCM, For additional information, refer to: Controller Area Network (CAN) Module Communications Network .

9. Carry out the network test.
   • If the scan tool responds with no communication for one or more modules, For additional information, refer to: Controller Area Network (CAN) Module Communications Network .
   • If the network test passes, retrieve and record continuous memory DTCs.

10. Clear the continuous DTCs and carry out the self-test diagnostics for the PCM.
11. If the DTCs retrieved are related to the concern, go to the appropriate Electronic Engine Controls article.
12. If no DTCs related to the concern are retrieved, continue the inspection and verification if a noise concern is related to the engine. For vibration concerns and noise concerns such as powertrain mounts, air intake system and starter GO to Symptom Chart - NVH.
13. NOTE: This procedure uses multiple tools/methods to help locate the source of engine noise. It may be necessary to repeatedly compare the sound between the tools/methods to help locate the source of the noise.

    Follow the steps below to help identify the source of engine noise. Compare the characteristics of the engine noise to those listed in the NVH chart.

    1. Using a stethoscope, try to locate the source of the engine noise. Note the location of any suspected noises heard with the stethoscope.

       Click here to view engine noise diagnosis using a stethoscope. 

       multimedia:A supplement to the article is available.
    2. If the noise is unclear using a stethoscope, attach ChassisEAR to multiple locations of the engine. Attach ChassisEAR to suspected areas of the noise and areas not suspected as the source of the noise for comparison purposes. ChassisEAR allow up to 6 clamps to locate the source of the noise. Instead of or in addition to using the ChassisEAR, EngineEAR can also be used. Wave or hold the EngineEAR over suspected areas of the engine to help identify the suspected noise.

       Click here to view engine noise diagnosis using ChassisEAR. 

       multimedia:A supplement to the article is available.

       Click here to view engine noise diagnosis using EngineEAR. 

       multimedia:A supplement to the article is available.
    3. If the noise is still unclear using the stethoscope, ChassisEAR or EngineEAR, connect the scan tool. Use the VCMM oscilloscope function to view and graph noise. Attach the VCMM accelerometers at the loudest suspected locations as determined previously by using the stethoscope, Chassis Ears or EngineEAR. Using the scan tool and VCMM accelerometers, graph the noise through the oscilloscope and determine if the noise is an upper or lower engine noise. For upper engine noise, place the accelerometers at either end of the valve cover. For lower engine noises, place the accelerometers at either end or side to side of the engine block.

       Click here to view engine noise diagnosis using VCMM and accelerometers. 

       multimedia:A supplement to the article is available.
    4. NOTE: ChassisEAR and EngineEAR allow the use of a microphone for listening. These tools may be connected directly to the VCMM by using a 3.5mm male to RCA female adapter.

       If the noise remains unclear or to verify the suspected noise from the stethoscope ChassisEAR, EngineEAR or graphed accelerometers, using a 3.5mm male to RCA female adapter, attach the ChassisEAR or EngineEAR to the VCMM. Graph all or some of the noises, as like the accelerometers.

       Click here to view engine noise diagnosis using VCMM and ChassisEAR. 

       multimedia:A supplement to the article is available.

       Click here to view engine noise diagnosis using VCMM and EngineEAR. 

       multimedia:A supplement to the article is available.
    5. If the suspected noise location still cannot be determined, using the oscilloscope function of the VCMM, graph any combination of the accelerometer(s), ChassisEAR and/or EngineEAR to compare or identify the suspected noise. All 4 ports on the VCMM may be utilized for graphing noise.

       Click here to view engine noise diagnosis using VCMM and ChassisEAR and accelerometer(s). 

       multimedia:A supplement to the article is available.

       Click here to view engine noise diagnosis using VCMM and EngineEAR and accelerometer(s). 

       multimedia:A supplement to the article is available.

14. After the noise is localized, note the characteristics of the noise, including type of noise, frequency and conditions when the noise occurs. Use the NVH chart to help identify the source of the noise.

    NVH Chart 

    NOTE: Possible sources and their listed actions are not limited to the symptoms provided below.Noise may be telegraphed from other areas or excited from associated parts and/or assemblies. The below chart of sources and actions are strictly suggestions and should be used as a guide.

    Symptom	Possible Source
    Drone type noise	Powertrain mount(s) Drivetrain
    Drumming noise - occurs inside the vehicle during idle or high idle, hot or cold. Very low-frequency drumming is very rpm dependent	Engine vibration excites the body resonances inducing interior noise Drivetrain
    Engine drumming noise - accompanied by vibration	Powertrain mount(s)
    Rattle	Drivetrain Lower end, excessive clearance between the connecting rod bearings and the crankshaft Lower end, worn or damaged crankshaft main bearings Valvetrain
    Rattle - occurs at idle or at light acceleration from a stop	Powertrain mount(s)
    Moaning	Drivetrain
    Whine/moan type noise - pitch increases or changes with vehicle speed	Powertrain mount(s)
    Clunk	Drivetrain
    Clunk - occurs when shifting from PARK or between REVERSE and DRIVE	Powertrain mounts Idle speed is too high
    Hooting	Air induction Powertrain mounts
    Accessory drive bearing hoot - occurs at idle or high idle in cold temperatures of approximately 4 deg.C (40 deg.F) or colder at the first start of the day	Accessory drive idler or tensioner pulley bearing is experiencing stick/slip between ball bearings and the bearing race
    Accessory drive belt noise, squeal or chirping	Defective/worn or incorrect accessory drive belt Misaligned pulley(s) Pulley runout Damaged or worn accessory drive component or idler Fluid contamination of the accessory drive belt or pulleys Damaged or worn accessory drive belt tensioner Damaged pulley grooves Damaged or worn coolant pump pulley
    Pop noise - happens approximately 30 seconds after cold start up	Turbocharger bypass valve
    Clunking/moaning/grinding noise	Coolant pump has excessive end play or imbalance
    Humming	Air Induction Powertrain mounts
    Whining	FEAD
    Whine/hum - occurs when unlocking the vehicle or opening the door with the engine off (GTDI only)	Fuel pump module
    Whine or moaning noise	Air intake system
    Whistling noise - normally accompanied with poor idle condition	Air intake system Turbocharger intake tube assembly leaking Loose connections or damage to air intake hoses and tubes Air leaks at turbine housing, blown joints or damaged exhaust Carbon build up in the turbine housing Turbocharger imbalance due to foreign object/damage Inoperative turbocharger bypass valve
    Whine or air rush type noise	Turbocharger Air Induction
    Chirp or whoosh sound	Turbocharger bypass valve Air Induction
    Hissing noise	Air Induction
    Hissing noise - occurs during idle or high idle that is apparent with the hood open	Vacuum leak Vehicles with a plastic intake manifold
    Grinding noise - occurs during engine cranking	Incorrect starter motor mounting Starter motor Incorrect starter motor drive engagement Drivetrain
    Engine noise, front of engine - knocking noise from lower front of engine	Damaged or separated crankshaft pulley/damper
    Tapping	Drivetrain Piston
    Engine noise, front of engine - ticking, tapping or rattling noise from the front of the engine	Timing drive components
    Engine noise, upper end - ticking noise near the fuel rail and intake manifold	Fuel rail clip Fuel injector Fuel injection pump (DI (direct injection) engines only)
    Engine noise, upper end - ticking, knocking or rattle noise that occurs during idle or high idle during the first cold start of the day and may disappear as the engine warms	Valve train noise (bled down lifter/lash adjuster) Cam Drive
    Engine noise, upper end - occurs mostly with a warm engine at light/medium acceleration	Worn or damaged spark plugs
    Engine noise, upper end - rattling noise from the valve train. Worse when the engine is cold	Low oil level Thin or diluted oil Low oil pressure Worn valve train components Worn valve guides Excessive runout of the valve seats on the valve face
    Engine noise, upper end - pinging noise	Gasoline octane too low KS operation Incorrect spark timing High operating temperature Spark plug Catalytic converter Cylinder head Valvetrain
    Engine noise, lower end - ticking or knocking noise near the oil filter adapter	Oil pump Lower end, excessive clearance between the connecting rod bearings and the crankshaft Lower end, worn or damaged crankshaft main bearings
    Engine noise, lower end - light knocking noise, also described as piston slap. Noise is most noticeable when the engine is cold with light to medium acceleration. The noise disappears as the engine warms	Excessive clearance between the piston and the cylinder wall
    Engine noise, lower end - light double knock or sharp rap sound. Occurs mostly with a warm engine at idle or low speeds in drive. Increases in relation to engine load. Associated with a poor lubrication history	Excessive clearance between the piston and the piston pin
    Engine noise, lower end - light knocking noise. The noise is most noticeable when the engine is warm. The noise tends to decrease when the vehicle is coasting or in neutral	Excessive clearance between the connecting rod bearings and the crankshaft
    Engine noise, lower end - deep knocking noise. The noise is most noticeable when the engine is warm, at lower rpm and under a light load and then at float	Worn or damaged crankshaft main bearings
    Engine noise, rear of engine - knocking noise at rear of engine	Damaged flywheel/flexplate
    Slapping	Drivetrain Piston
    Knocking	Drivetrain
    Engine vibration - vibration felt at all times	Excessive engine pulley runout Damaged or worn accessory component
    Engine vibration - at idle, a low-frequency vibration (5-20 Hz) or mild shake that is felt through the seat/ floorpan	Cylinder misfire Engine or torque converter out of balance
    Engine vibration - is felt with increases and decreases in engine rpm	Powertrain mount(s) Engine or transmission grounded to chassis
    Engine vibration - increases intensity as the engine rpm is increased	Engine out-of-balance
    Engine vibration - mostly at coast/neutral coast. Condition improves with vehicle acceleration	Combustion instability
    Engine vibration or shudder - occurs with light to medium acceleration above 56 km/h (35 mph)	Worn or damaged spark plugs Plugged fuel injector Contaminated fuel
    Bongo	Balance shaft
    Chatter	Valvetrain
    Chirping	FEAD Piston Rings Valvetrain
    Clicking	Fuel PCV Valvetrain
    Clatter	Cam Drive Piston
    Crickets	Cam Drive
    Dieseling	Lower end, excessive clearance between the connecting rod bearings and the crankshaft Lower end, worn or damaged crankshaft main bearings Piston
    Quacking	Cam Drive FEAD
    Scratching	Cam Drive Drivetrain Lower end, excessive clearance between the connecting rod bearings and the crankshaft Lower end, worn or damaged crankshaft main bearings
    Scraping	Cam Drive Drivetrain Lower end, excessive clearance between the connecting rod bearings and the crankshaft Lower end, worn or damaged crankshaft main bearings
    Squeaking	Cam Drive Drivetrain Lower end, excessive clearance between the connecting rod bearings and the crankshaft Lower end, worn or damaged crankshaft main bearings
    Squealing	Cam Drive Drivetrain Lower end, excessive clearance between the connecting rod bearings and the crankshaft Lower end, worn or damaged crankshaft main bearings
    Thumping	Drivetrain Lower end, excessive clearance between the connecting rod bearings and the crankshaft Lower end, worn or damaged crankshaft main bearings
    Tin-Like	Drivetrain Cylinder Head Manifold